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    GitHub Logo HIP-1084: Zero Cost EthereumTransaction on Success

    Author Nana Essilfie-Conduah, Richard Bair
    Working Group Richard Bair, Atul Mahamuni, Stanimir Stoyanov
    Requested By Relay Operators
    Discussions-To https://github.com/hashgraph/hedera-improvement-proposal/discussions/1083
    Status Last Call ⓘ
    Needs Council Approval Yes ⓘ
    Review period ends ⓘ Wed, 29 Jan 2025 07:00:00 +0000
    Type Standards Track ⓘ
    Category Service ⓘ
    Created 2024-11-20
    Updated 2025-01-15
    Requires 410

    Table of Contents

    Abstract

    Updates the rules for charging fees for EthereumTransactions, so that the payer of an EthereumTransaction will only incur a fee if the transaction fails due diligence checks.

    Motivation

    Today, relay operators must pay the EthereumTransaction HAPI fee for every transaction they submit on behalf of an Externally Owned Account (EOA). Currently, for every simple EthereumTransaction, this fee is the hbar equivalent of $0.0001, based on the exchange rate. Although this fee is very low, it effectively compels relay operators on Hedera to adopt a non-standard business model to cover these costs, which are then passed on to the users. Users are also burdened with understanding this more complex business model, which negatively impacts their experience.

    This situation acts as a friction point for EOAs looking to access cost-effective relay operators on the Hedera public network.

    Rationale

    On Ethereum, all execution costs are paid for by the ‘sender’ who created, signed, and submitted the transaction. Hedera follows a similar approach for ContractCallTransactions. However, Hedera charges an additional fee for each EthereumTransaction submitted via JSON-RPC relays. This fee serves as a defense against a malicious JSON-RPC relay that might send malformed transactions to the network, where there would be no one to pay for the processing of those transactions. This fee is unnecessary for successful transactions since the intrinsic gas fee covers the base costs (gossip & consensus). Therefore, this HIP proposes that the fee for submitting EthereumTransactions to the network should only be charged if the JSON-RPC relay submits a transaction that fails due diligence checks, such that the EOA cannot be charged for the overhead of gossip and consensus.

    User stories

    1. As a relay operator, I want to submit an EthereumTransaction on behalf of an EOA without paying additional fees.
    2. As a node operator, I want to charge relays that submit transactions that cannot be charged to the EOA.
    3. As a user, I want to use the same pricing structure and have the same user experience for Hedera relays as with other networks.

    Specification

    Definitions:

    • evm tx: The RLP encoded transaction bytes defined by the Ethereum yellow paper that form a standard Ethereum transaction
    • relay: A system that, given an evm tx, wraps it in an HAPI EthereumTransaction and submits it to Hedera. This is also the payer for the EthereumTransaction. See TransactionBody.transactionID
    • EOA: The account that created and signed the evm tx and submitted it to a relay. This is the from in the Ethereum Transaction Schema often noted as (tx.from)

    Smart Contract Creation and Execution Transactions

    The relay will only be charged if handling of the EthereumTransaction fails before any bytecodes are executed. In other words, the relay is charged when one of the pre-requisite checks for EthereumTransaction fails, regardless of the execution status of the transaction itself once it begins smart contract creation or execution in the EVM.

    Examples:

    • The relay is charged if the evm tx cannot be parsed or is otherwise malformed
    • The relay is charged if the EOA specified in the evm tx refers to a non-existent account
    • The relay is charged if the evm tx was not properly signed by the keys of the EOA
    • The relay is charged if the EOA has insufficient funds to pay the intrinsic gas fee
    • The relay is charged if the nonce check fails
    • The relay is not charged if the contract is called but concludes with an error code
    • The relay is not charged if the contract is called and concludes without error

    In summary the relay account is not charged if the EthereumTransaction transaction completes in a CONTRACT_REVERT_EXECUTED or SUCCESS HAPI response code, all other responses codes will result in a charge to the relay account.

    ### Regular Transactions

    A “regular transaction” is a simple HBAR crypto transfer between two accounts. The relay will be charged for any failure of the transaction. This is required to maintain compatibility with the semantics in Ethereum, where a regular transaction will not be included in a block or executed if it will not succeed.

    Example:

    • The relay is charged if the evm tx cannot be parsed or is otherwise malformed
    • The relay is charged if the EOA specified in the evm tx refers to a non-existent account
    • The relay is charged if the evm tx was not properly signed by the keys of the EOA
    • The relay is charged if the EOA has insufficient funds to pay the intrinsic gas fee and the transfer
    • The relay is charged if the receiver has receiverSigRequired enabled
    • The relay is charged if the receiver doesn’t exist, must be auto-created, and the EOA has insufficient funds to pay for the account creation
    • The relay is charged if the nonce check fails

    In summary the relay account is not charged if the EthereumTransaction transaction completes in a SUCCESS HAPI response code, all other response codes will result in a charge to the relay account.

    Backwards Compatibility

    No changes to transaction execution or record stream externalization is made in this HIP. EthereumTransaction will continue to work and will only see a reduction in cost on success or contract revert cases.

    Security Implications

    No changes in security.

    References

    Copyright/license

    This document is licensed under the Apache License, Version 2.0 – see LICENSE or (https://www.apache.org/licenses/LICENSE-2.0)

    Citation

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